Function of the rim

[A440A@aol.com]

  Dave asks: 
 
> Are there any other obvious clinkers in that test? >>
 
i wrote:  
> Hmm.  when I took it, I missed the question "Why is quartersawn wood used 
in 
> soundboards?" 
>     The "correct" answer was "  to increase stability. I don't think that 
is 
> why quarter sawn wood is used, at all.  

John sez: 
>>I can see your point this is a bit misleading. But radial cut spruce is 
about twice as stable as tangential sawn spruce in relation to changes 
in humidity. You would clearly have a lot more problems with tuning 
stability and considerably more damage from compression set if you used 
flat sawn spruce.  >>

      There is no question that quarter sawn wood is more stable.  However, 
when asking "why" it was used in musical instruments, there are many other 
considerations that may have equal or more weight.  Wooden organ pipes use 
quarter-sawn pieces for the front of the pipe, even though the other three sides are 
usually made of much inferior wood cuts.( I don't pretend to know the 
acoustical properties of these pipes, but stabilty isn't suggested by such exclusive 
use).  
   Also, we see its use in instruments like 15th century harpsichords, where 
stability is virtually non-existant to start with.  It is also seen in 17th 
century hurdy-gurdys, in which the structure provides a lot of stabilty, no 
matter what orientation is used. If not for acoustical reasons, I can't hazard a 
guess.  Violins, too.  
   In the eras before central heating and air conditioning, there were far 
less changes in humidity, so I would surmise that humidity-related instability 
was much less of a factor than it would be today.  So I don't think the "why" 
for quarter-sawn is definitive enough to use for a test question like it is.  
   I do know that a quarter-sawn piece of mature, long-leaf pine will last as 
long as hardwood if used in a dance floor, (personal experience).     
regards, 
Ed Foote RPT